Punch press



Oct. 21, 1941. B. KNUTSEN ET AL 2,260,182

' PUNCH PRESS Filed Feb. 26, 1941 5 Sheets-Sheet l INVENTORS 5 erro i hn/wt sem BY Jb lzn W Qu't 5 A 77' ORNE Y or an l Oct. 21, 1941. B. KNUTSEN ETAL 2,260,182

PUNCH PRESS 5 Sheets-Sheet 2 Filed Feb. 26, 1941 INVENTORS Berni hnwtsen John N Qumls Oct. 21, 1941. B. KNUTSEN ET AL PUNCH PRESS 3 Sheets-Sheet 5 Filed Feb. 26, 1941 t" w 10 A 00 e Patented Oct. 21, 1941 PUNCH PRESS Bemt Knutsen, Brooklyn, and John W. Quis,

Maspeth, Long Island, N. Y., assignors to Callahan Can Machine 00., Inc.,' Brooklyn, N. Y.

Application February 26, 1941, Serial No. 380,590

6 Claims.

This invention relates to a new and useful improvement in a punch press designed particularly for the punching of disks for bottle caps and other purposes from sheets of thin metal or other sheet material.

One of the most common uses of such a press is in the making of the universally-known and used crown caps, and for this reason a press suitable for this purpose is illustrated and described herein, but it will be understood that the invention is not limited to this particular type of press, or this particular use.

As a general rule, punch presses of this type are provided with a plurality of punches and dies so arranged that an equivalent number of disks are simultaneously punched and formed into caps in a single operation.

The material employed is usually thin metal in the form of rectangular sheets of a size suitable for the punch press employed and for the feeding mechanism. It is fed progressively, sheet by sheet, to the punches in such a way as to leave a minimum of scrap.

As this method has been practiced, the initial punching operation upon the entering end of the sheet of metal employs only the first row of punches, the second row operating idly. When this operation is completed, the sheet is fed forward so that it is positioned under both rows of punches, which, upon the next punching operation, punch out two rows or twice as many as produced by the initial punching operation. Thereafter two rows of disks are punched simultaneously until the following edge of the sheet is reached, where the last row of disks is punched by the second row of punches, the first row operating idly. Therefore, at both ends of the sheet there is a loss of 50% in the punching capacity of the press, and, since it has been the practice not to start the punching operation upon one sheet until the previous sheet has been completely punched, this loss is repeated for each sheet and may result in a total capacity loss per day of as much as 300 or 400 gross of disks and caps.

The object of this invention is to substantially eliminate this loss and to make available substantially the full punching capacity of the press.

As heretofore stated, a press suitable for the punching and forming of crown caps is shown in the drawings, of which:

Figure 1 is a plan view of a part of such a press; showing in particular the sheet-feeding mechanism;

Figures 2 and 3 are diagrammatic illustrations 55 numbered l8 and the second row is.

of one stage of the feeding of the sheets into the press; 1

Figures 4 and 5 are similar illustrations of a second stage;

Figures 6 and 7 are similar illustrations of a 4 third stage; and

Figures 8 and 9 are similar illustrations of a fourth or final stage.

As shown in Figure 1, the punch press consists in part of a frame or bed I, which supports a slide 2, which can be reciprocated longitudinally by means of gear-segment 3, the teeth of which mesh with a rack 4 on slide 2. Gearsegment 3 is keyed to a shaft 5, which is so connected to a source of power (not shown) that the reciprocation of slide 2 is synchronized with the operation of the punches, as will hereinafter be explained in detail. Upon slide 2 is mounted a rack bar 6, which carries three series of feed dogs la--'lq, Biz-80, and 9. Slide 2 also carries a second identical feed rack parallel to the feed rack 6 and provided with an identical series of identically-positioned dogs, which have. been similarly numbered in Figures 2-9, to insure that the sheet is fed to the punches in accurate alignment.

Tne jaws of the feed dogs operate in longitudinal slots in a bed-plate H], the upper surface of which is at the same elevation as the upper edge of slide 2 so that the jaws normally project above it to substantally the same extent as above the upper edge of slide 2. This bedplate supports the sheet of metal l2 during its progress through the press. Each feed dog, with the exception of dogs 9, is pivotally mounted so that the jaws of those which are under the sheet of metal will swing downwardly below the surface of bed-plate [0 to permit the sheet to rest upon the bed-plate.

Above the bed-plate I0 is a hold-down II 0 any suitable design which frictionally holds the sheet of metal l2 against bed-plate ID in the positions to which it is moved by the feed dogs. This may consist of a plate or grid of any suitable design supported from a convenient part [3 of the frame and caused to exert pressure upon sheet l2 by springs H. A second hold-down M for a similar purpose is provided adjacent the punches. This is maintained in frictional engagement with the sheet of metal I2 by means of a spring l5 between it and arm l6 mounted on a suitable part I! of theframe of the press.

Two rows of 8 punches each are diagrammatically shown in the drawings, the front row being The second row is staggered with respect to the first so that when the punching of the sheet of -metal is completed, practically no waste metalwill be left between the holes as will be seen from Figure 9. Below the two rows of punches are positioned corresponding rows of dies, two of which are shown at 20 and 2| designed to produce bottle caps of the, crown type, or whatever shape .is desired, from the disks cut by the punches.

The sheets of metal are fed ontobed-plate 10 of the press by any suitable feeding mechanism,

diagrammatically illustrated by a pair of rolls" 22 and 23. y

' The press is also provided with a transverse sheet over-lapping step 24, set into bed-plate I'll, so that its rear edge is flush therewith and its front edge projects above the bed-plate some what more than the thicknessv of.the sheet of metal'. The front edge is also substantially tangential to the first row of punches; The purpose of this step is to lift the entering edge of one sheet of metal over the followingedge of the preceding sheet so that they can be overlapped, as will be hereinafter explained.

Over-lapping. step 2 lzis broken, as shown, for example, in Figure 5, so as not tointerrupt the slots in bed-plate ill, in which. thejaws of the feed'dogs operate.

- The press operates as follows Assume that a sheet of metal [2 has beenfed by the. feeding device diagrammatically indicated by rolls 22 and 23 onto bed-plate l under hold-downl t, and'is finally positionedvwith its following edge in front of feed dogs 8a. When slide 2 ismoved to the left, the entering edge of sheet 12 will be moved by dog.8a into/position under the first row of punches 18 for the first punching operation. as shown in Figure 1. .When the punches descend the first row of. disks is punched out, leaving holes 25in. sheet l 2, as. shown in- Figure 5. It

will be noted that only one row of disks ispunched, the second row of punches [9 operating -idly. In this respect. this invention follows the old practice. Meanwhile slide 2 is moved to the right, carryingrack bar 6 and the feed dogs withit, so that dog lq is positioned beyond the following edge of sheet 12 in readiness to feed the sheet forward again after this first punching operation, as shown in Figures 2 and 3. I

The next sheet-feeding motion positions sheet l2 under both rows of punches, as shown in Figures 4 and 5, and the ensuing punching operation'will produce 16 disks and will leave 16 holes in the sheet'corresponding in position to the punches l8 and 19, as shown in Figurefi.

. The feeding and punching sequence is repeated,

the sheet being fedforward step by step by successive dogs, kc-lo, etc., until sheet l2is positioned for the last possible two-row punching operation. As shown in Figures 6 and 7, sheet I 2 has been fed forward by dog lb and has slipped off the-front edge of step 2d. When the punches descend they will produce two rows of disks, and will leave in sheet 12- holes corresponding in position to the punches l8 and I9, as shown sheet, corresponding in position to; that of punch-,. es I9,;;as shown in FigureS,

However, while sheet l2 has been fed into the punches by the feed dogs as described, the next sheet 26 has been gradually fed onto bed-plate H] by rolls 22 and 23, as indicated in Figures 2-5, its entering edge being some distance behind the following edge of sheet [2. Finally, the following edge of sheet 26 will be ejected by rolls 22 and 23 and will fall'inw front of feed dogs 9, when slide 2 is in its extreme right position. The next move to the left of slide 2 will cause feed dogs 9 to move sheet 26 towards the punch- The next reciprocation of slide 2 to the right and then to the left will permit dogs 80 to engage the following edge of sheet 26 and to feed it again towards the punches. Dog 811 then assumes the task, as shown in Fig. 6, followed by dog 811 as shown in Figure 8.

The distances between centers of feed dogs Ba.8c are all greater than the distances between centers of the feed dogs la-'lq, and the re- -ciprocating motion of slide 2 is greater than'that as there is no such space between the following edgeofsheet 2E, and the operating feeddogs Therefore, the feeding of sheet 26 by the dogs 311-30 series is faster-than of the Sit-8c series.

the feeding of sheet [2 by the feed dogs' of'the 'lal-q series. In other words, sheet 26 gradually catches up with sheet l2 as sheet' I2 is fed The spacing of the feed through the punches. dogs Bar-8c is such that when sheet i2 is positioned as shown in Figure 6to receive its final double punching, its following 'edge lies substantially directly under the entering edgeof sheet 26" These edges are not in contact because, also; as;

shown in Figure 6, the following edge of sheet l'l has slipped from the front edge of sheet over lapping step 24 and the entering edge of sheet 2 6 is lying upon the top of step 24.

punches i9. Since, as stated, the feeding mo-' tion of the feed dogs Zia-8c is greater thanthat. of the'feed dogs lalq, and since the entering edge of sheet 26' already overlies the'follewing; edge "of sheet E2, the next motion offslide 2 to theleft will cause the entering edge of sheet 23' to overlap'the following: edge of'sheet I2, as shown.

in'fFigures 8 and 9. Consequently, whenthe'fl' punches descend, punches l9 will punch thejlast row of holes in sheet I2"and punches [8", will "simultaneously punch the first row of holes in sheet Thereafter sheet !2. Duringjthe punching of sheefZF, the

sheet?! is fed'into the press, and finally" caused to. overlap sheet 26, so that the final punchingfoperation of sheet 2 6]and'the' initial punching of the third sheet 2lis si'multaneously performed, I i H In each'case the entering edge ofv one. sheet is lapped over the following edge of "theprecding sheet atthe; proper time and tothe properdissheet [2 is removed from the press by any suitable ejecting device, and sheet 26 is fed through the punches by the feed dogs la,l q inthe same manner as described with respect-to formed by the punches It will be noted from the several figures that the two rows of punches are not only staggered with respect to each other, but are separated by a distance between their centers of a little more than a diameter and a half, so that alternate rows are punched by each double punching operation. Therefore, for the last double punching operation on a sheet, sheet I2, for example, as shown in Figures 6 and '7, the punches I8 are positioned substantially at the following edge of sheet l2, whereas punches 19 are separated from them by the intervening row of holes 28 already l8 in the preceding punching operation. This leaves a space 29 to the left and below each hole 28 of unpunched metal large enough for another row of disks. The final punching operation on sheet I2 produces a row of disks from these spaces 29 to the right and below each hole 28. That is to say, the row of disks nearest the following edge of sheet I2 is punched before the entering edge of sheet 26 is caused to overlap sheet l2, or, in other words, to overlap the row of holes nearest the edge of sheet l2 indicated by the numeral 30 of Figure 9.

In the next punching operation the two rows of punches straddle the overlap, as shown in Figure 9, to produce the last row of disks actually punched out of sheet I2, although the next to the last row in location, and the first row of disks punched out of sheet 26, although, in position, the second row.

It will be realized, of course, that the punches may vary in number and arrangement and in number of rows, the major requirement being that they be arranged so that no punching will occur through the overlap portions of two succeeding sheets.

It will also be realized, of course, that the application of this invention to presses of different design may require more or less alteration in the operations described in order to meet the essential requirement that successive sheets of material be overlapped at the proper time and to the correct amount to permit the punches to operate upon the sheets simultaneously substantially as described.

We claim:

1. The method of punching sheet material, which consists of simultaneously punching alternate rows of holes therein until the following edge is reached, then lapping the leading edge of another sheet over the last row of holes punched in the first sheet and then simultaneously punching the next to the last row of holes in the first sheet and the initial row of holes in the second sheet.

2. The method of punching sheet material, which consists of simultaneously punching alternate rows of holes therein until the following edge is reached, then lapping the leading edge of another sheet over the following edge of the first sheet and then simultaneously punching the next to the last row of holes in the first sheet and the initial row of holes in the second sheet.

3. The method of punching sheet material in a punch press provided with two or more rows of simultaneously-operated punches spaced so as to punch alternate rows of holes in sheet material, which consists of feeding sheet material intermittently and progressively under said punches until the last row of holes has been punched by the first row of punches, then feeding said sheet so that its following edge lies behind the first row of punches and simultaneously feeding a second sheet of material so that its leading edge lies below said first row of punches and overlaps the following edge of said first sheet between the first and second row of punches, and then punching a final row of holes in the first sheet by the second row of punches and an initial row of holes in the second sheet by the first row of punches.

4. In a punch press, means for intermittently and progressively feeding a sheet of material under the punches, means for similarly feeding a second sheet of material towards the punches at a rate sufficiently fast to cause said second sheet to overlap said first sheet between the next to last and last punching operations on said first sheet, and means for guiding the leading edge of said second sheet over the following edge of said first sheet at the beginning of said overlapping.

5. In a punch press provided with punches and means for feeding a plurality of sheets of sheet material to the punches one after the other so that the leading edge of one sheet overlaps the following edge of the preceding sheet before the punching of the first-mentioned sheet is completed, means for guiding the leading edge of said first-mentioned sheet over the following edge of said preceding sheet at the beginning of the overlapping of said sheet.

6. In a punch press provided with punches, a bed-plate and means for feeding a plurality of sheets of sheet material along said bed-plate to the punches one after the other so that'the leading edge of one sheet overlaps the following edge of the preceding sheet before the punching of the first-mentioned sheet is completed, means for guiding the leading edge of said first-mentioned sheet over the following edge of said preceding sheet at the beginning of the overlapping of said sheets, consisting of a step sloping upwardly from the bed-plate to a height greater than the thickness of a. sheet.

BERNT KNUTSEN. JOHN W. QUIS. 

